The application of image filters combined with the nonlinear regression analysis on optical auto-focusing

This paper presents an optical auto-focusing system that is implemented by integrating a real-time auto-focusing algorithm, an image capturing and processing module and a stepper motor. Several image filters are tested and compared through the system for their effects on suppressing noise to accelerate the auto-focusing procedure. Besides, a nonlinear regression method is applied in the data analysis for the system to quickly move the stepper motor to the focus. The concise and effective algorithm can be applied on digital cameras for auto-focusing with noise reduction.